What material are most Lego bricks made of?

Most LEGO bricks are made of acrylonitrile butadiene styrene, or ABS plastic.

ABS is an engineering thermoplastic valued for the properties LEGO bricks need: rigidity, toughness, dimensional stability, and the ability to hold strong, consistent colors. Those qualities help a brick survive repeated assembly while maintaining the controlled friction—often called clutch power—that keeps models together.

LEGO adopted ABS for most standard bricks in 1963, replacing cellulose acetate. The change improved stability and durability, helping pieces keep their shape and color over long periods. Manufacturing begins with colored plastic granules, which are melted and injected into precision moulds. After cooling, the parts are checked for dimensions, color, and connection performance.

“Most” matters because LEGO uses other materials for some elements. Flexible parts, transparent pieces, tires, strings, and certain specialized components may use plastics or rubber better suited to their function. Plant-based polyethylene has also been used for selected botanical elements, but that does not mean ordinary bricks are made from it.

ABS is also why the answer is not PVC, nylon, or polycarbonate for standard bricks. The material was selected because its balance of strength, finish, and mouldability suits LEGO’s tightly controlled building system.